【摘要】 椭圆转子发动机通过转子上的进、排气口换气，具有3个燃烧室且曲轴转速是转子转速的2倍，其换气特性和排气特征与传统活塞往复式发动机及三角转子发动机有明显区别．本文利用GT-Power软件建立了符合椭圆转子发动机工作特点的一维模型，以研究此类型发动机的换气过程特点、排气脉冲特性及排气歧管长度对其的影响规律，为高换气效率排气系统结构设计提供参考．研究结果表明：完整的排气过程可以划分为4个阶段：阶段1、2是废气流出的主要时期，占总排气量的90%以上；阶段3、4进、排气口同时开启但无法实现有效的扫气过程，且废气回流现象明显，导致缸内残余废气率提高．相邻燃烧室之间存在进、排气口叠开期，每个燃烧室排气末期均对应后燃烧室的排气初期，后燃烧室废气大量流出的同时窜漏入相邻燃烧室的现象较为明显，即燃烧室内的残余废气量同时受到自身排气过程和相邻燃烧室排气过程的综合影响．排气歧管长度变化对气口全开期的影响大于气口叠开期，气口全开期排气量是叠开期的3倍以上．计算长度范围内最优歧管长度可使排气过程排气量提高3.21%，并使气口叠开期的进气量提高32.80%．实现更好的排气效果的同时利于进气过程，有效地减少了阶段3废气向进气道的回流量，最终降低燃烧室内的残余废气率，实现换气效率的提高．更多还原

【Abstract】 The elliptical rotor engine possesses three combustion chambers and has a crankshaft speed twice that of the rotor speed. Its air exchange and exhaust characteristics evidently differ from those of traditional piston reciprocating engines and triangle rotor engines. In this paper,GT-Power software is used to construct a one-dimensional model that is consistent with the operating characteristics of an elliptical rotor engine to investigate the characteristics of the air exchange process,exhaust pulse characteristics,and the influence of exhaust manifold length on this type of engine and provides a reference for the structural design of exhaust systems with a high air exchange efficiency. The results show that the complete exhaust process can be divided into four phases. The phase 1 and phase 2,accounting for more than 90% of the total exhaust volume,are the main stages of exhaust gas outflow. The inlet and exhaust ports are opened simultaneously in the phase 3 and phase 4. However,the effective scavenging process cannot be realized,and exhaust gas reflux is evident in these two phases,resulting in an increase in the residual exhaust gas rate in the cylinder. The inlet and exhaust ports overlap between adjacent combustion chambers,and the exhaust end of each combustion chamber corresponds to the exhaust initial stage of the rear combustion chamber. A large amount of exhaust gas in the rear combustion chamber evidently leaks into the adjacent combustion chamber;that is,the residual exhaust gas amount in the combustion chamber is simultaneously affected by the exhaust process of its own and those of adjacent combustion chambers. The exhaust manifold length exerts a greater influence on the full opening period than on the valve overlap period,and exhaust volume in the full opening period is more than three times that in the valve overlap period. Within the calculated length range,the optimal manifold length configuration increases exhaust volume during the exhaust process by 3.21%,while simultaneously boosting intake air volume during valve overlap period by 32.80%. In addition to achieving a better exhaust effect,it is beneficial to the intake process,effectively reducing the phase 3 exhaust gas reflux to the intake port and,ultimately,the residual exhaust gas rate in the combustion chamber to improve the air exchange efficiency.更多还原